Clothes treating apparatus

ABSTRACT

The present invention relates to a clothes treating apparatus that comprise: a cabinet that forms the external appearance and includes a door on the top thereof for extracting or introducing laundry; a tub provided within the cabinet so as to store washing water; a drum rotatably provided within the tub so as to receive the laundry; a balancer provided to rotate together with the drum and to maintain dynamic equilibrium of the drum using water supplied thereinto; and a water supply unit that supplies water to the balancer. The balancer includes a drain unit that drains the water received in the balancer when the rotating speed of the drum is lower than or equal to a specified speed.

TECHNICAL FIELD

The present invention relates to a laundry treating apparatus and a method of controlling the same.

BACKGROUND ART

A conventional laundry treating apparatus includes a cabinet forming an external appearance, a tub provided inside the cabinet, a drum rotatably provided inside the tub to wash laundry, and a motor of which rotary shaft is fixed to the drum by passing through the tub to rotate the drum.

The drum may be rotated without maintaining dynamic equilibrium depending on a position of laundry stored therein.

Dynamic equilibrium means ‘the state that a centrifugal force or a moment made by the centrifugal force is 0 with respect to a rotary shaft when a rotor is rotated’. In case of a rigid body, if mass distribution of the rigid body is uniformly maintained around the rotary shaft, dynamic equilibrium is maintained.

Therefore, dynamic equilibrium in the laundry treating apparatus may be understood that mass distribution of laundry is within an allowable range around the rotary shaft of the drum when the drum is rotated in a state that laundry is stored in the drum (the case that the drum is rotated while being vibrated within the allowable range).

In contrast, the state that dynamic equilibrium has been broken (i.e., unbalance) in the laundry treating apparatus means that mass distribution is not maintained uniformly around the rotary shaft of the drum when the drum is rotated. This unbalance is generated when laundry is not distributed uniformly inside the drum.

If the drum of the unbalance state is rotated, the drum is vibrated, and the vibration of the drum is delivered to the tub or the cabinet, whereby noise may be caused.

The conventional laundry treating apparatus includes balancing units to solve unbalance of the drum. The balancing units provided in the conventional laundry treating apparatus are ball balancers or fluid balancers having a ball or a fluid received in a housing fixed to the drum.

The ball balancer or the fluid balancer included in the conventional laundry treating apparatus functions to control unbalance by moving the ball or the fluid to an opposite side of a direction where laundry causing unbalance is located when a rotation track of the drum wobbles by means of the laundry causing unbalance.

However, the aforementioned unbalance control is useful for a steady state that vibration of the drum is within a certain range, whereas a problem occurs in that the unbalance control is not effective at a transient vibration state of the drum. Also, the conventional balancing unit has a structure that it is difficult to immediately solve unbalance (actively solve unbalance) when unbalance is generated.

DISCLOSURE Technical Problem

An object of the present invention is to provide a laundry treating apparatus that may solve unbalance by supplying water to balancers while a drum is being rotated without stopping its rotation in an unbalance state that laundry is not distributed uniformly.

Another object of the present invention is to provide a laundry treating apparatus that includes a structure for discharging water supplied to balancers of a drum after solving unbalance.

Still another object of the present invention is to provide a laundry treating apparatus that includes balancers for actively solving unbalance by supplying water thereto at upper and lower portions of a drum while the drum is being rotated.

Further still another object of the present invention is to provide a laundry treating apparatus that includes at least one balancer provided at an upper portion or a lower portion of a drum to actively solve unbalance by supplying water thereto while the drum is being rotated.

Technical Solution

To achieve these objects and other advantages and in accordance with the purpose of the invention, the present invention provides a laundry treating apparatus comprising a cabinet forming an external appearance and including a door provided on a top surface to take or put laundry out of or into the top surface; a tub provided inside the cabinet to store washing water therein; a drum rotatably provided inside the tub to receive the laundry therein; a balancer provided in a single body to be rotated together with the drum and provided to maintain dynamic equilibrium of the drum by supplying water thereinto; and a water supply unit supplying water to the balancer, wherein the balancer includes a drainage unit provided to drain the water received in the balancer when a rotating speed of the drum reaches a predetermined speed or less.

Also, the balancer is provided on at least one of an upper portion and a lower portion of the drum.

Also, the balancer includes a housing in which water is stored, at least one or more barriers partitioning the inside of the housing, and an inlet provided in the housing to allow the water to enter the inside of the housing.

Also, the drainage unit is provided at a circumferential inner side of the housing to drain the water inside the housing when the rotating speed of the drum reaches a predetermined speed or less.

Also, the barriers include a main barrier provided to partition the inside of the housing, and at least one or more sub barriers provided in a space partitioned by the main barrier to prevent the water received in the housing from being concentrated on one side.

Also, the sub barriers are provided to have their respective heights which gradually become higher along a rotating direction of the drum.

Also, the water supply unit includes a water supply nozzle provided to spray water to a desired position in a state that the balancer is rotated, and a water supply guider guiding the water sprayed by the water supply nozzle to enter the inside of the balancer.

Also, the water supply nozzle is provided to be communicated with a washing water supply unit for supplying washing water to the tub.

Also, the laundry treating apparatus further comprises a fluid balancer or a ball balancer provided at an upper portion or lower portion of the drum, having a fluid or a ball therein to maintain dynamic equilibrium of the drum.

Also, the drum is provided such that its rotary shaft is vertical to a lower surface of the cabinet.

Also, each of the drum and the tub includes an opening on an upper surface to put or take laundry into or out of the upper surface.

Also, the drainage unit is provided to drain the water received in the balancer in a direction vertical to a gravity direction.

Also, the barrier is extended in a direction vertical to a gravity direction to partition the inside of the housing.

Also, the laundry treating apparatus may further comprise a driving unit for rotating the drum. The driving unit includes a motor providing a rotating force, a shaft having one end communicated with the motor and the other end communicated with the drum, wherein the shaft is provided in parallel with a gravity direction.

Advantageous Effects

According to the present invention, it is possible to solve unbalance by supplying water to balancers while a drum is being rotated without stopping its rotation in an unbalance state that laundry is not distributed uniformly.

Also, according to the present invention, since a laundry treating apparatus includes a structure for discharging water supplied to balancers of a drum after solving unbalance, the water supplied to the balancers may be discharged efficiently.

Also, according to the present invention, it is possible to actively solve unbalance by supplying water balancers at upper and lower portions of a drum while the drum is being rotated.

Also, according to the present invention, since a laundry treating apparatus includes at least one balancer provided at an upper portion or a lower portion of a drum to supply water thereto while the drum is being rotated, unbalance may be solved more efficiently.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example of a laundry treating apparatus according to the present invention.

FIG. 2 illustrates an example of a sensor unit provided in the present invention.

FIG. 3 illustrates an example of an upper balancer provided in the present invention.

FIGS. 4, 5 and 6 illustrate an example of a lower balancer provided in the present invention.

FIG. 7 illustrates an example of a method for controlling unbalance generated in a laundry treating apparatus of the present invention.

FIG. 8 is a flow chart illustrating an example of a control method for determining a water supply amount and a water supply position of water supplied to an upper balancer and a lower balancer provided in a laundry treating apparatus of the present invention.

FIGS. 9 and 10 illustrate an example of water supply units provided in an upper balancer and a lower balancer to supply water.

BEST MODE FOR CARRYING OUT THE INVENTION

Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Meanwhile, elements or control method of apparatuses which will be described below are only intended to describe the embodiments of the present invention and are not intended to restrict the scope of the present invention. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.

FIG. 1 illustrates an example of a laundry treating apparatus according to the present invention.

Referring to FIG. 1, the laundry treating apparatus according to the present invention includes a cabinet 10 for forming an external appearance, a tub 20 provided inside the cabinet 10, storing washing water therein, and a drum 30 rotatably provided inside the tub 20, for receiving laundry therein.

Since the laundry treating apparatus of the present invention is a top loading type for putting or taking laundry into or out of a top surface, a rotary shaft of the drum 30 may be provided to be vertical to a lower surface of the cabinet 10.

The cabinet 10 may include a cabinet opening 12 and a door 111 on the top surface of the cabinet 10, wherein the cabinet opening 12 is provided to put or take laundry into or out of the top surface of the cabinet, and the door 11 is rotatably provided to open or close the cabinet opening 12.

The tub 20 may include a tub opening 11 on a top surface thereof to put or take laundry into or out of the top surface.

Although not shown, the drum 30 may include a drum opening (not shown) for allowing laundry to be put into or taken out of the cabinet opening 12 and the tub opening 21.

That is, a user may put laundry into the drum 30 sequentially through the cabinet opening 12, the tub opening 21 and the drum opening (not shown) by opening the door 11 rotatably provided on the top surface of the cabinet 10.

Also, the laundry treating apparatus of the present invention may include a water supply unit 70 for supplying water to the tub 20 and a drainage unit 60 for draining washing water from the tub 20.

The water supply unit 70 may include a water supply hose 71 and a water supply valve 73. One end of the water supply hose 71 may be protruded toward the outside of the cabinet 10 such that water may externally be supplied thereto, and the other end of the water supply hose 71 may be communicated with one side of the tub 20 such that the externally supplied water may be supplied to the tub 20. The water supply valve 73 may be provided in the water supply hose 71 to control the amount of water supplied to the tub 20 through the water supply hose 71.

The drainage unit 60 may include a drainage hose 61 and a drainage valve 63. The drainage hose 61 has one end communicated with the tub 20 and the other end protruded to the outside of the cabinet 10, whereby the washing water drained from the tub 20 may be discharged to the outside of the laundry treating apparatus. The drainage valve 63 may be provided in the drainage hose 61 to control the amount of the washing water discharged to the outside of the laundry treating apparatus through the drainage hose 61.

The drum 30 is rotatably provided, and the laundry treating apparatus of the present invention may include a power unit 40 for rotating the drum 30.

The power unit 40 may include a shaft 41 provided to be communicated with the drum 30 to deliver a rotational force generated in the power unit 40 to the drum 30, a stator 45 for generating a rotating magnetic force for rotating the shaft 41, a rotor 47 rotatably provided inside the stator 45 in a single body with the shaft 41, and a bearing housing 43 provided to support gravity of the shaft 41 which is rotated.

The shaft 41 may be provided to be vertical to a lower surface of the cabinet 10.

In other words, the shaft 41 may be provided in parallel with a gravity direction.

A BLDC motor typically used in the related art of the laundry treating apparatus may be used as the power unit 40 used in the laundry treating apparatus of the present invention. Since the BLDC motor is already known, its detailed description will be omitted.

Since the drum 30 is rotatably provided, vibration generated in the drum 30 may be delivered to the tub 20, and the vibration delivered to the tub 20 may again delivered to the cabinet 10.

If the tub 20 is vibrated, horizontal displacement or vertical displacement is generated. For this reason, interference between the tub 20 and the cabinet 10 is generated, whereby noise or damage may occur.

To avoid noise or damage, the laundry treating apparatus of the present invention may include a vibration unit for preventing vibration of the tub 20 from being delivered to the cabinet 10.

The vibration unit may include a first holder 51 provided on one surface of the cabinet 10, a second holder 53 provided on one surface of the tub 20, a connector 55 connecting the first holder 51 with the second holder 53, and an elastic member 57 provided at one end of the connector 55, providing an elastic force to the second holder 53 and the connector 55.

Also, the connector 55 may include a first clamp portion 551 provided at one end to prevent the connector 55 from being detached from the first holder 51, and a second clamp portion 553 provided at the other end to prevent the connector 55 from being detached from the second holder 53.

The drum 30 of the laundry treating apparatus according to the present invention may include balancers 31 and 32 on at least one of an upper portion or a lower portion of the drum 30 to prevent unbalance from being generated in the laundry stored in the drum 30 while the drum 30 is being rotated as described above.

As shown in FIG. 1, the upper balancer 31 may be provided on the upper portion of the drum 30, and the lower balancer 32 may be provided on the lower portion of the drum 30.

As described above, the conventional ball balancer or fluid balancer is provided to solve unbalance in such a manner that a ball or fluid moves passively in an opposite direction of a wobble direction of laundry stored in the drum 30 when the laundry wobbles.

However, the balancers 31 and 32 of the laundry treating apparatus according to the present invention may effectively solve unbalance even in a transient state as well as a steady state.

In more detail, the balancers 31 and 32 may be active balancers that identify a position where unbalance is generated by sensing a vibration state of the drum 30 or the tub 20 and then actively solve unbalance by supplying water in an opposite direction of the position where unbalance is generated.

However, if the active balancers 31 and 32 are provided on the upper and lower portions of the drum 30, it may act as load in view of the material cost and efficiency of production. Therefore, the active balancer 31 or 32 may be provided on at least one of the upper and lower portions of the drum 30, and the conventional ball balancer or fluid balancer may be provided on the other portion.

Preferably, since it is more effective to solve unbalance that the aforementioned active balancers 31 and 32 are provided on the upper and lower portions of the drum 30, the laundry treating apparatus of the present invention will be described on the assumption that the active balancers 31 and 32 are provided on the upper and lower portions of the drum 30.

To solve unbalance in the laundry treating apparatus of the present invention, the vibration state of the tub 20 or the drum 30 should be sensed. To this end, the laundry treating apparatus may further include a sensor unit.

The sensor unit may include a top sensor 81 provided on the upper surface of the tub 20 to sense vertical vibration on the upper surface of the tub 20, an upper sensor 83 provided on an upper portion of a side of the tub 20 to sense horizontal vibration at the upper portion of the side of the tub 20, and a lower sensor 85 provided on a lower portion of the side of the tub 20 to sense horizontal vibration at the lower portion of the side of the tub 20.

In more detail, the sensors used in the sensor unit may be provided as optical sensors. The top sensor 81, the upper sensor 83 and the lower sensor 85 may respectively derive sinusoidal shaped profiles by sensing a vertical distance between the upper surface of the tub 20 and the upper surface of the cabinet 10, a horizontal distance between the upper portion of the side of the tub 20 and the upper portion of the side of the cabinet 10, and a horizontal distance between the lower portion of the side of the tub 20 and the lower portion of the side of the cabinet 10 in real time.

The controller (not shown) determines a portion of the drum 30 where laundry causing unbalance is concentrated on by modeling the profiles sensed by the respective sensors of the sensor unit, and sprays water to the positions of the upper balancer 31 and the lower balancer 32 to solve unbalance.

FIG. 2 illustrates an example of a sensor unit 80 provided in the present invention.

Referring to FIG. 2(a), the laundry treating apparatus of the present invention may include a top sensor 81 provided on the upper surface of the tub 20 to measure a distance YC from the upper surface of the tub 20 to the upper surface of the cabinet 10.

Referring to FIG. 2(b), the laundry treating apparatus of the present invention may include an upper sensor 83 provided on the upper portion of the side of the tub 20 to measure a distance YT from the upper portion of the side of the tub 20 to the upper portion of the side of the cabinet 10.

Referring to FIG. 2(c), the laundry treating apparatus of the present invention may include a lower sensor 85 provided on the lower portion of the side of the tub 20 to measure a distance YB from the lower portion of the side of the tub 20 to the lower portion of the side of the cabinet 10.

More preferably, the top sensor 81, the upper sensor 83 and the lower sensor 85 are provided as optical sensors.

The top sensor 81 serves to sense vertical vibration of the tub 20, and the upper sensor 83 and the lower sensor 85 serve to sense horizontal vibration of the tub 20.

Basically, since the upper sensor 83 and the lower sensor 85 serve to sense horizontal vibration, there is no big problem in sensing the position of the laundry causing unbalance even though one of the two sensors is only provided.

However, if the laundry is located in the drum 30 in a diagonal direction to cause unbalance, for example, if the laundry is located at the upper portion of the right side of the drum 30 and at the same time is located at the lower portion of the left side of the drum 30, unbalance is generated, whereby noise of the laundry treating apparatus may be generated.

Therefore, to solve unbalance through more precise control, it is preferable that the upper sensor 83 and the lower sensor 85 are respectively provided at the upper portion of the side of the tub 20 and the lower portion of the side of the tub 20.

FIG. 3 illustrates an example of an upper balancer provided in the present invention.

Referring to FIG. 3(a), the laundry treating apparatus of the present invention may include an upper balancer 31 provided in a hollow shape to solve unbalance at the upper portion of the drum 30.

Since the upper balancer 31 is provided to surround the drum 30 and the laundry should be put into or taken out of the drum 30, it is preferable that the upper balancer 31 is provided in a hollow shape provided with an opening at the center.

The upper balancer 31 may include an upper housing 311 providing a space for receiving water for solving unbalance, a first barrier portion 313 provided inside the upper housing 311, a first water supply unit 315 provided to solve unbalance by supplying water to the inside of the upper housing 311, and a first drainage unit 317 for discharging the water received in the upper housing 311 after solving unbalance.

The upper housing 311 may include a first upper housing 3111 forming an inner circumference surface of the upper balancer 31, and a second upper housing 3113 for forming an outer circumference surface of the upper balancer 31.

In more detail, a section of the first upper housing 3111 may be provided in a vertical direction to form the inner circumference surface of the upper balancer 31, and a section of the second upper housing 3113 may be provided to form the lower surface, the outer circumference surface and the upper surface of the upper balancer 31.

An upper surface of the second upper housing 3113 may be provided to be spaced apart from the first upper housing 3111 at a predetermined interval.

This is to provide a path for supplying water to the upper balancer 31 to solve unbalance. In other words, the upper surface of the first upper housing 3111 and the upper surface of the second upper housing 3113 may be formed to be spaced apart from each other to form the path that can supply water.

That is, the shapes of the first upper housing 3111 and the second upper housing 3113 have only to be provided to form the path for supplying water to the upper balancer 31 as described above without limitation to the shapes shown in FIG. 3.

The shape of the first water supply unit 315 is not limited to the shape shown in FIG. 3. That is, the shape of the first water supply unit 315 has only to be provided to supply water to the upper housing 311 without stopping rotation of the drum 30 in a state that the drum 30 is rotated.

The first drainage unit 317 may be provided at the lower end of the first upper housing 3111.

The laundry treating apparatus of the present invention may solve unbalance generated in the drum 30 by supplying water in an opposite direction of the laundry in a state that the drum 30 is rotated.

After unbalance is solved, if the water supplied into the upper housing 311 is not drained, another unbalance may be generated.

Therefore, after unbalance is solved in a state that the drum 30 is rotated, rotation of the drum 30 should be stopped, and the water received in the upper housing 311 should be drained in a state that rotation of the drum 30 is stopped. Therefore, it is preferable that the first drainage unit 317 is provided at the lower portion of the inner side of the upper housing 311, that is, the lower portion of the first upper housing 3111.

That is, the first drainage unit 317 may be provided to drain the water received in the upper housing 311 in a direction vertical to a gravity direction.

While the drum 30 is being rotated, the upper balancer 31, the upper housing 311 and the water supplied into the upper housing 311 perform circular motion, whereby a centrifugal force acts on an outer direction of a radius direction based on the rotation center of the drum 30.

Therefore, the water supplied into the upper housing 311 is not drained due to the centrifugal force while the drum 30 is being rotated, whereby unbalance may be solved. After unbalance is solved, rotation of the drum 30 is stopped, whereby the water received in the upper housing 311 may be drained into the drum through the first drainage unit 317.

The first barrier portion 313 may include a plurality of first barriers provided inside the upper housing 311 to partition the inside of the upper housing 311.

Although the first barrier portion 313 is provided to partition the inside of the upper housing 311 into 8 spaces in FIG. 3(b), the number of the inner spaces of the upper housing 311, which are partitioned by the first barrier portion 313, is not limited to the example of FIG. 3(b). That is, the number of the first barriers 313 has only to be provided to solve unbalance, and may be provided differently if necessary.

FIGS. 4, 5 and 6 illustrate an example of a lower balancer provided in the present invention.

Referring to FIG. 4, the laundry treating apparatus of the present invention may include a lower balancer 32 provided in a hollow shape to solve balance at the lower portion of the drum 30.

The laundry treating apparatus of the present invention may further include a power unit 40 for rotating the drum 30. The power unit 40 may be provided on the lower surface of the drum 30. Therefore, it is preferable that the lower balancer 32 is provided in a hollow shape to prevent interference with the power unit 40 from occurring.

The lower balancer 32 may include a lower housing 321 providing a space for receiving water for solving unbalance, a second barrier portion 323 provided inside the lower housing 321, a second water supply unit 325 provided to solve unbalance by supplying water to the inside of the lower housing 321, and a second drainage unit 327 for discharging the water received in the lower housing 321 after solving unbalance.

The lower housing 321 may include a first lower housing 3211 forming an inner circumference surface of the lower balancer 32, and a second lower housing 3213 for forming an outer circumference surface of the lower balancer 32.

In more detail, a section of the first lower housing 3211 may be provided in a vertical direction to form the inner circumference surface of the lower balancer 32, and a section of the second lower housing 3213 may be provided to form the lower surface, the outer circumference surface and the upper surface of the lower balancer 32.

An upper surface of the second lower housing 3213 may be provided to be spaced apart from the first lower housing 3211 at a predetermined interval.

This is to provide a path for supplying water to the lower balancer 32 to solve unbalance. In other words, the upper surface of the first lower housing 3211 and the upper surface of the second lower housing 3213 may be formed to be spaced apart from each other to form the path that can supply water.

That is, the shapes of the first lower housing 3211 and the second lower housing 3213 have only to be provided to form the path for supplying water to the lower balancer 32 as described above without limitation to the shapes shown in FIG. 4.

The shape of the second water supply unit 325 is not limited to the shape shown in FIG. 4. That is, the shape of the second water supply unit 325 has only to be provided to supply water to the lower housing 321 without stopping rotation of the drum 30 in a state that the drum 30 is rotated.

The second drainage unit 327 may be provided at the lower end of the first lower housing 3211.

The laundry treating apparatus of the present invention may solve unbalance generated in the drum 30 by supplying water in an opposite direction of the laundry in a state that the drum 30 is rotated.

After unbalance is solved, if the water supplied into the lower housing 321 is not drained, another unbalance may be generated.

Therefore, after unbalance is solved in a state that the drum 30 is rotated, rotation of the drum 30 should be stopped, and the water received in the lower housing 321 should be drained in a state that rotation of the drum 30 is stopped. Therefore, it is preferable that the second drainage unit 327 is provided at the lower portion of the inner side of the lower housing 321, that is, the lower portion of the first lower housing 3211.

While the drum 30 is being rotated, the lower balancer 32, the lower housing 321 and the water supplied into the lower housing 321 perform circular motion, whereby a centrifugal force acts on an outer direction of a radius direction based on the rotation center of the drum 30.

Therefore, the water supplied into the lower housing 321 is not drained due to the centrifugal force while the drum 30 is being rotated, whereby unbalance may be solved. After unbalance is solved, rotation of the drum 30 is stopped, whereby the water received in the lower housing 321 may be drained into the drum through the second drainage unit 327.

The second barrier portion 323 may include a plurality of second barriers provided inside the lower housing 321 to partition the inside of the lower housing 321.

Although the second barrier portion 323 is provided to partition the inside of the lower housing 321 into 8 spaces in FIG. 5, the number of the inner spaces of the lower housing 321, which are partitioned by the second barrier portion 323, is not limited to the example of FIG. 5. That is, the number of the second barriers 323 has only to be provided to solve unbalance, and may be provided differently if necessary.

The second barrier portion 323 provided in the lower balancer 32 will be described with reference to FIG. 6. Although the structure of the second barrier portion 323 of the lower balancer 32 is only shown in FIG. 6, this structure may equally be applied to the upper balancer 31.

The second barrier portion 323 may be provided to be extended in a direction vertical to a gravity direction so as to partition the inside of the lower housing 321.

The second barrier portion 323 may include second main barriers 3231 partitioning the inside of the lower housing 321 into a plurality of spaces, and at least one or more second sub barriers 3233 provided in the partitioned spaces.

Unbalance generated in the laundry treating apparatus of the present invention may be solved even in the case that the second barrier portion 323 includes the second main barriers 3231 only.

However, since the drum 30 is rotated, the water received in the lower housing 321 is concentrated on an opposite direction of a rotational direction by its inertia, whereby unbalance cannot be solved efficiently.

To solve this, the upper balancer 31 and the lower balancer 32 of the laundry treating apparatus according to the present invention may include at least one or more second sub barriers 3233 provided between the main barriers 3231 to have their respective heights different from each other.

In more detail, the second sub barriers 3233 may be provided to have their heights which become gradually higher along the rotational direction of the drum 30.

In this case, concentration of the water received in the upper housing 311 or the lower housing 321 due to inertia may be prevented from occurring, whereby unbalance may be solved more efficiently.

For example, in FIG. 6, one second main barrier 3231 is provided and five second sub barriers 3233 are provided.

The five second sub barriers 3233 may be provided as B6, B5, B4, B3 and B2 of which heights become higher in due order, and the second main barrier 3231 may be provided as the highest B1.

However, the number of second sub barriers 3233 is not limited to this embodiment, and may be provided differently depending on the need of a user.

The second main barrier 3231 should be provided to partition the lower housing 321. However, since the second sub barriers 3233 are intended to prevent concentration of the water received in the lower housing 321 from occurring as described above, the second sub barriers 3233 should be provided so as not to partition the lower housing 321.

That is, the water received in the lower housing 321 should be provided to freely move among the plurality of second sub barriers 3233.

Therefore, as shown in FIG. 6, it is preferable that a length of the lower surface of the second sub barriers 3233 is shorter than a length of the lower surface of the second main barrier 3231 as much as A in a diameter direction.

However, the length difference between the lower surface of the second main barrier 3231 and the lower surface of the second sub barrier 3233 may be provided differently if necessary, and is not limited to the ratio shown in FIG. 6.

FIG. 7 illustrates an example of a method for controlling unbalance generated in a laundry treating apparatus of the present invention.

In more detail, the method of FIG. 7 relates to a control method for determining a position of water supplied to the upper balancer 31 or the lower balancer 32 to solve unbalance generated in the laundry treating apparatus of the present invention more efficiently.

As described above, unbalance means that mass distribution is not maintained uniformly around the rotary shaft of the drum 30 when the drum 30 is rotated. This may mean that the drum 30 is rotated in a state that the laundry in the drum 30 is concentrated on one side.

The laundry treating apparatus of the present invention solves unbalance by identifying the concentrated position of the laundry and spraying water in an opposite direction of the concentrated position of the laundry based on the rotary shaft of the drum 30. Since the laundry has its mass and rotated together with the drum 30, in case of a primary control, an inertia error ε1 is generated by inertia as shown in FIG. 7(a).

Therefore, to overcome the inertia error ε1 according to the primary control, a secondary control is performed considering the primary control value.

Meanwhile, even though the secondary control is performed considering the inertia error ε1 generated in the primary control as shown in FIG. 7(b), a counter electromotive force error ε2 may be generated.

The counter electromotive force means an electromotive force generated in an opposite direction of an electromotive force of a power source in either an armature coil of an electric motor or a primary coil of a transformer.

That is, although the secondary control is performed in an opposite direction to compensate for the inertia error ε1, the counter electromotive force error ε2 is generated by the counter electromotive force.

Therefore, the laundry treating apparatus of the present invention may include a third control for more precise control as shown in FIG. 7(c).

The third control may control the balancers 31 and 32 by considering the counter electromotive force error ε2 generated in the secondary control.

A residual error ε3 may be generated through the aforementioned control. If this residual error ε3 is within a preset allowable error mε, it is possible to efficiently solve unbalance.

FIG. 8 is a flow chart illustrating an example of a control method for determining a water supply amount and a water supply position of water supplied to an upper balancer and a lower balancer provided in a laundry treating apparatus of the present invention.

Referring to FIG. 8, the control method of the laundry treating apparatus according to the present invention may include a distance measuring step S10 of measuring an upper distance YT and a lower distance YB through the upper sensor 83 and the lower sensor 85, and a measurement comparing step S20 of determining whether the upper distance YT and the lower distance YB measured in the distance measuring step are the same as each other.

If profiles of the upper distance YT and the lower distance YB are the same as each other in the measurement comparing step S20, the laundry in the drum 30 is concentrated on the upper portion of the drum 30 or the lower portion of the drum 30. Since the laundry is not concentrated in a diagonal direction when viewed from a front end of the drum 30, it is possible to solve unbalance by supplying water to only one of the upper balancer 31 and the lower balancer 32.

Although the control method for supplying water to the lower balancer 32 only is shown in this embodiment, the control method is not limited to this embodiment and water may be supplied to only the upper balancer 31 if necessary.

Therefore, if the profiles of the upper distance YT and the lower distance YB are the same as each other in the measurement comparing step S20, the control method of the laundry treating apparatus according to the present invention may include a lower amplitude measuring step S30 of measuring an amplitude of the lower distance YB from the profile of the lower distance YB, and a lower phase measuring step S40 of measuring a phase of the lower distance YB.

The control method may further include a lower water supply amount determining step S31 of determining a water supply amount of the lower balancer 32 through the amplitude of the lower distance YB measured in the lower amplitude measuring step S30, and a first lower water supply position determining step S41 of determining a water supply position of the lower balancer through the phase of the lower distance YB.

Afterwards, the laundry treating apparatus of the present invention may solve unbalance through a first lower balancer water supply step S50 of supplying water to the lower balancer 32 based on the water supply amount and the water supply position, which are determined by the lower water supply amount determining step S31 and the first lower water supply position determining step S41.

If the profiles of the upper distance YT and the lower distance YB are not the same as each other in the measurement comparing step S20, since the laundry is concentrated in a diagonal direction when viewed from a front end of the drum 30, water should be supplied to both the upper balancer 31 and the lower balancer 32 to solve unbalance.

In this case, the water should be supplied to the upper balancer 31 and the lower balancer 32 unlike the first lower balancer water supply step S50. Since the upper balancer 31 and the lower balancer 32 are provided on the upper and lower portions of the drum 30 in a single body with the drum 30 to be rotated together with the drum 30, the upper balancer 31 and the lower balancer 32 are coupled to each other. Unbalance cannot be solved by simple water supply depending on the amplitude and the phase of the profiles of the upper distance YT and the lower distance YB.

In other words, the phase of the profile of the upper distance YT used for control of the upper balancer 31 should again be applied to the control of the lower balancer 32.

Therefore, if the profiles of the upper distance YT and the lower distance YB are not the same as each other in the measurement comparing step S20, the control method of the laundry treating apparatus may include an upper amplitude measuring step S60 of measuring an amplitude of the upper distance YT, an upper water supply amount determining step S61 of determining a water supply amount of the upper balancer 31 through the determined amplitude of the upper distance YT, an upper phase measuring step S70 of measuring a phase of the upper distance YT, an upper water supply position determining step S71 of determining a water supply position of the upper balancer 31 through the measured phase of the upper distance, and an upper balancer water supply step S80 of supplying water to the upper balancer 31 based on the water supply amount and the water supply position, which are determined by the upper water supply amount determining step S61 and the upper water supply position determining step S71.

The control method may further include a lower balancer water supply amount determining step S31 of determining a water supply amount of the lower balancer through the lower amplitude measured in the lower amplitude measuring step of 30 of measuring the lower amplitude, a phase difference computing step S90 of computing a phase difference between the lower phase measured in the lower phase measuring step S40 of measuring a lower phase and the upper phase measured in the upper phase measuring step S70 of measuring the upper phase, a second lower water supply position determining step S91 of determining a water supply position of the lower balancer by using the phase difference between the upper phase and the lower phase, which is computed by the phase difference computing step S90, and a second lower balancer water supply step S51 of supplying water to the lower balancer based on the water supply amount and the water supply position, which are determined by the lower water supply amount determining step S31 and the second lower water supply position determining step S91.

FIGS. 9 and 10 illustrate an example of water supply units provided in an upper balancer and a lower balancer to supply water.

Referring to FIG. 9, since the laundry treating apparatus of the present invention should supply water to the upper balancer 31 in a state that the drum 30 is rotated, the laundry treating apparatus may further include a first water supply unit 315.

The first water supply unit 315 may include a first water supply nozzle 3153 which is a means for supplying water into the upper balancer 31 by using a predetermined pressure, and a first water supply guider 3151 provided to guide the water sprayed from the first water supply nozzle 3153 into the upper housing 311.

The water supplied from the first water supply unit 315 moves into the upper housing 311. In more detail, the water may be supplied into the upper housing 311 through a path formed by the first and second upper housings 3111 and 3113 spaced apart from each other at a predetermined distance.

Referring to FIG. 10, since the laundry treating apparatus of the present invention should supply water to the lower balancer 32 in a state that the drum 30 is rotated, the laundry treating apparatus may further include a second water supply unit 325.

The second water supply unit 325 may include a second water supply nozzle 3253 which is a means for supplying water into the lower balancer 32 by using a predetermined pressure, and a second water supply guider 3251 provided to guide the water sprayed from the second water supply nozzle 3253 into the lower housing 321.

The water supplied from the second water supply unit 325 moves into the lower housing 321. In more detail, the water may be supplied into the lower housing 321 through a path formed by the first and second lower housings 3211 and 3213 spaced apart from each other at a predetermined distance.

It will be apparent to those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit and essential characteristics of the invention. Thus, the above embodiments are to be considered in all respects as illustrative and not restrictive. The scope of the invention should be determined by reasonable interpretation of the appended claims and all change which comes within the equivalent scope of the invention are included in the scope of the invention. 

1. A laundry treating apparatus comprising a cabinet forming an external appearance and including a door provided on a top surface to take or put laundry out of or into the top surface; a tub provided inside the cabinet to store washing water therein; a drum rotatably provided inside the tub to receive the laundry therein; a balancer provided in a single body to be rotated together with the drum and provided to maintain dynamic equilibrium of the drum by supplying water thereinto; and a water supply unit supplying water to the balancer, wherein the balancer includes a drainage unit provided to drain the water received in the balancer when a rotating speed of the drum reaches a predetermined speed or less.
 2. The laundry treating apparatus according to claim 1, wherein the balancer is provided on at least one of an upper portion and a lower portion of the drum.
 3. The laundry treating apparatus according to claim 1, wherein the balancer includes: a housing in which water is stored; at least one or more barriers partitioning the inside of the housing; and an inlet provided in the housing to allow the water to enter the inside of the housing.
 4. The laundry treating apparatus according to claim 3, wherein the drainage unit is provided at a circumferential inner side of the housing to drain the water inside the housing when the rotating speed of the drum reaches a predetermined speed or less.
 5. The laundry treating apparatus according to claim 3, wherein the barriers include: a main barrier provided to partition the inside of the housing; and at least one or more sub barriers provided in a space partitioned by the main barrier to prevent the water received in the housing from being concentrated on one side.
 6. The laundry treating apparatus according to claim 5, wherein the sub barriers are provided to have their respective heights which gradually become higher along a rotating direction of the drum.
 7. The laundry treating apparatus according to claim 1, wherein the water supply unit includes: a water supply nozzle provided to spray water to a desired position in a state that the balancer is rotated; and a water supply guider guiding the water sprayed by the water supply nozzle to enter the inside of the balancer.
 8. The laundry treating apparatus according to claim 7, wherein the water supply nozzle is provided to be communicated with a washing water supply unit for supplying washing water to the tub.
 9. The laundry treating apparatus according to claim 1, further comprising a fluid balancer or a ball balancer provided at an upper portion or lower portion of the drum, having a fluid or a ball therein to maintain dynamic equilibrium of the drum.
 10. The laundry treating apparatus according to claim 1, wherein the drum is provided such that its rotary shaft is vertical to a lower surface of the cabinet.
 11. The laundry treating apparatus according to claim 1, wherein each of the drum and the tub includes an opening on an upper surface to put or take laundry into or out of the upper surface.
 12. The laundry treating apparatus according to claim 1, wherein the drainage unit is provided to drain the water received in the balancer in a direction vertical to a gravity direction.
 13. The laundry treating apparatus according to claim 3, wherein the barrier is extended in a direction vertical to a gravity direction to partition the inside of the housing.
 14. The laundry treating apparatus according to claim 1, further comprising a driving unit for rotating the drum, wherein the driving unit includes: a motor providing a rotating force; a shaft having one end communicated with the motor and the other end communicated with the drum, the shaft being provided in parallel with a gravity direction. 